I have done it several ways but prefer to band them. I like the Callicrate bander since it can even be used on mature bulls. I sell bulls mainly so that is the reason for that. I don't want to send a cull bull to the sale barn that hasn't been cut regardless of the age. It works great and not much discomfort (at least that is what they tell me). Just be sure to give them a tetanus shot when you do it. Using a knife is fine if you do it when they are young.